Simple Intelligent Robot Implemented by Single Chip Microcomputer

introduction

With the continuous development of microelectronics technology, it is easy to combine computer technology with measurement and control technology to form an intelligent measurement and control system. At present, people can completely design and manufacture simple intelligent robots with certain special functions .

1 Design concept and overall plan

1.1 Design ideas of simple intelligent robots

The robot can walk along the guide line in any area, automatically bypass obstacles, and walk along the light source under the guidance of a light source. At the same time, it can detect metal pieces buried underground, emit sound and light indication information, and store and display the number of detected breakpoints and the distance between each breakpoint and the starting line in real time. Finally, it can stop at a designated location and display the time of the entire running process.

1.2 Overall design and block diagram

This design uses AT89C51 microcontroller as the detection and control core. Infrared photoelectric sensors are used to detect black lines and obstacles on the road surface, metal sensors are used to detect metal iron sheets under the road surface, photoelectric encoders are used to measure distance, photoresistors are used to detect and judge the location of the garage, and PWM (pulse width modulation) technology is used to dynamically control the rotation direction and speed of the motor. Software programming is used to achieve precise control of the robot's movement, obstacle avoidance, and stop, as well as the storage and display of detection data. By optimizing the combination of circuits, all resources of the 51 microcontroller can be utilized to the maximum extent.

Port P0 is used for digital tube display, port P1 is used for PWM drive control of the motor, and ports P2 and P3 are used for data acquisition and interrupt control of the sensor. The advantages of this are: making full use of the internal resources of the microcontroller and reducing the cost of the overall design. The overall scheme of this solution is shown in Figure 1.

2. Hardware composition and design principle of the system

The hardware part of this system consists of a single-chip microcomputer unit, a sensor unit, a power supply unit, an audible and visual alarm unit, a keyboard input unit, a motor control unit and a display unit, as shown in Figure 2.

2.1 Microcontroller Unit

This system uses AT89C51 single-chip microcomputer as the central processor. Its main task is to scan the signal input by the keyboard to start the robot, and continuously read the data collected by the sensor during the robot's walking process. After processing the obtained data, it generates PWM pulses with different duty cycles to control the motor according to different situations, and sends the relevant data to the display unit for dynamic display to generate sound and light alarm signals. Among them, P0 is used for dynamic display of digital tubes, P1.0-P1.5 controls 2 motors, P1.6 and P1.7 are independent keyboard interfaces, P2 is connected to the sensor, P3.2 is connected to the photoelectric code disk for mileage, P3.7 is connected to the sound and light alarm unit, and P3.4, P3.5, and P3.6 are connected to the light-emitting diodes used to display the number of breakpoints.

2.2 Motor Control Unit

This robot uses a dual-motor dual-wheel driven car as its base. The two motors independently control the left and right wheels, and the turning function is achieved by the different speeds of the two motors. It can also turn on the spot, which is easy to control. Traditional cars are driven by power motors and steering motors, and the turning angle is difficult to control, making them inconvenient to use.

The motor control circuit uses an H-type drive circuit composed of high-power transistors BDl39 and BDl40. The microcontroller generates PWM pulses with different duty cycles to accurately adjust the motor speed. This circuit works in the saturation or cut-off state of the transistor, avoiding the transistor consumption when working in the linear amplification area, and can maximize efficiency; the H-type circuit ensures that the motor speed and direction can be easily controlled; the speed and stability of the electronic switch can also fully meet the needs. The whole set of drive circuits is a widely used motor drive technology. The circuit is shown in Figure 3.

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